1. Field of the Invention
The present invention relates to a monitoring technique around a moving body such as a vehicle, etc., around which fish-eye cameras mounted on the moving body monitor. More particularly, the present invention relates to a monitoring apparatus around a moving body and a method of displaying a bird's-eye view image, for obtaining a bird's-eye view image based on the images picked up by fish-eye cameras in order to ensure safe driving for the driver.
2. Description of the Related Art
Up to now, a monitoring apparatus used for a moving body has been using an image processing technique for generating a composite image based on the images picked up by a plurality of cameras in order to support safe driving at the time of driving the moving body.
For example, according to Japanese Patent No. 3300334, as shown in FIG. 13, in a monitoring apparatus 1, a plurality of cameras 3 are attached to arbitrary positions of a moving body 2. The monitoring apparatus 1 generates a composite image based on the images obtained by the plurality of cameras 3 attached to the arbitrary positions to display the composite image in the vehicle 2, thereby making it possible to contribute to safe driving of the vehicle 2. The composite image is produced by image processing such that a hypothetical view point P is set above the vehicle 2 in advance and the vehicle 2 is looked down upon from this hypothetical view point P.
In Japanese Patent No. 3300334, for generating a bird's-eye view image, a mapping table in which corresponding relationships between the pixels of the composite image and the pixel data of each camera image are described is used.
Since the image captured from the hypothetical view point P is a wide-angle image including part of the periphery of the vehicle 2, it is possible for the driver of the vehicle 2 to safely drive while viewing the wide-angle image.
On the other hand, according to the monitoring apparatus 1, since an ordinary camera having a standard lens is used for each camera 3, the image areas covered by these cameras are relatively small. In order to cover the areas necessary for the driving of the moving body, a large number of cameras must be installed. In this case, it is necessary to perform the composite processing of many images, and thus the image processing becomes complicated and it becomes necessary to take much processing time.
Further, the mapping table must be created in advance, and thus it is necessary to take much work and time for creating that table.
Furthermore, another monitoring apparatus around a vehicle has been disclosed in Japanese Unexamined Patent Application Publication No. 2003-196645.
According to the Japanese Unexamined Patent Application Publication No. 2003-196645, as shown in FIG. 14, in a monitoring apparatus 11, a blind-spot camera 13 is installed at the blind-spot position of the driver in a vehicle 12. In addition, a camera using a fish-eye lens (hereinafter, referred to as fish-eye camera) 14 is installed in a backward direction at the central position of the rear trunk of the vehicle 12. The fish-eye image of the backward area of the moving body obtained from the fish-eye camera 14 is dewarping processed into a usual two-dimensional image to provide the driver with a usual image of the blind spot of the backward area of the moving body.
According to the monitoring apparatus 11, when the vehicle 12 moves forward or backward, an obstacle which exists in front of or at the back of the vehicle, or a body such as another vehicle, etc., which comes into the backward area becomes visible in a visible area, and thus making it possible to contribute to safer driving.